The present invention relates to a method of interoffice trunk testing, and more particularly to a method of increasing trunk testing capacity and efficiency while evaluating interoffice transmission quality across a TDM network of all trunks in a central office.
To provide communication across a communications network the calling parties at each end are connected by a circuit. TDM communications networks typically provide a channel dedicated to the circuit for the duration of the call. Network operators have central offices which include a large number of lines, or trunks, which connect to other central offices across the network to form portions of the circuits for these calls.
Network operators routinely test each trunk on a regular basis, such as once a month, to ensure that they can properly connect the central offices and support quality voice transmission in an interoffice connection. In today's central offices, automated trunk testing is typically accomplished using software processes which attempt to test every trunk in the office by seizing an idle trunk, initiating an interoffice test call, allocating test equipment at both ends of the trunk, running a test to verify the transmission quality of the connection, and then disconnect the test equipment. Each trunk is tested during a testing cycle. The duration of each trunk test typically takes between 10 and 60 seconds to execute depending on the type of trunk being tested. Though multiple trunk tests can be run simultaneously, this can consume valuable call processing resources.
Typically in the past, central offices have not exceeded approximately 90 thousand trunks per office. A testing cycle, testing each of the 90,000 trunks could be completed in about a month thereby meeting the network operator's testing requirements. However, to meet the increased communications needs of customers network operators have been increasing the capacity of their central offices to handle larger numbers of calls. With the introduction of large circuit tandems, the number of trunks at central offices have grown to 256,000 trunks or more.
As the number of trunks has increased, the testing time required to complete a test cycle testing all of the trunks has become too long to meet the testing requirements of the network operators. One solution to this problem would be to test more trunks simultaneously, though this would require purchasing more testing equipment and/or consuming more valuable call processing resources. It is desirable to provide an improved trunk testing scheme which provides a higher testing capacity to ensure reliable trunk operation while minimizing the need for additional testing equipment and processing resources.